I'm new to metal detecting and would like some advice on which product to buy for the beach. I will use it primarily in salt water sand, targets would be coins and jewelery. Total unit waterproof unit not necessary, just the coil. I have zero experience, but am techno savvy and not afraid of electronics. My price range is $200-$500, I don't want something that I'll upgrading after gaining experience, but can't afford top of the line. Specific make, model recommendations appreciated